Marine Technical Training Academy

  Raw Water-Cooling Systems Raw water-cooling systems draw water from outside the boat (seawater or lake water). Water is pumped from the source to the engine block then the engine circulation pump forces the raw water thru the engine block and the water is expelled thru the exhaust. On larger engines and inboard engines, the raw water pump is located inside the boat and is driven by a v-belt or directly off of the crankshaft. There are hidden dangers that can accumulate over time causing you to spend big Dollars on repairs. The danger is using salt water as a coolant in your engine. Salt water can be highly corrosive. Get here the Marine Diesel Engines Book where you can find all the information on this and many other topics. Get the book Raw Water Pumps This pump sucks water from the sea. It typically goes through a strainer as it is sucked towards the pump. Saltwater Pump and Impeller Kit: A flexible impeller pump provides an efficient solution to most raw water pumping needs. T...

  Battery Storage Capacity The Amp-hour (Ah) Capacity of a battery tries to quantify the amount of usable energy it can store at a nominal voltage. Storage capacity is additive when batteries are wired in parallel but not if they are wired in series. When two 6V, 100Ah batteries are wired in Series, the voltage is doubled but the amp-hour capacity remains 100Ah (Total Power = 1200 Watt-hours). You may decide to wire batteries in series because a single 12V battery with the right storage capacity is simply too heavy, unwieldy, or awkward to lift into place. Batteries consisting of fewer cells (and hence lower voltage) in series can provide the same storage capacity yet be portable.  Two 6V, 100Ah batteries wired in Parallel will have a total storage capacity of 200Ah at 6V (or 1200 Watt-hours) Battery banks wired in Series-Parallel are even more complicated. Here, four 6V cells are wired in two "strings" of 12VDC that were then wired in parallel. Using 6V, 100Ah batteries, thi...